Apparatus for use in conserving water in a furnace cooling system



Sept. 24, 1968 WESTERF-N ETAL 3,402,765

APPARATUS FOR USE IN CONSERVING WATER IN A FURNACE COOLING SYSTEM Filed Oct. 24, 1966 a sheets-sheet 1 INVENTOR HERBERT W. WESTE BY WILLIAM H. KIMBALL MM 7 M ATTQRNEYS Se t. 24, 1968 H- w. WE EREN ETAI- 3,402,765.

APPARATUS FOR USE IN CONSERVING WATER IN A FURNACE COOLING'SYSTEM Filed Oct. 24, 1966 5 Sheets-Sheet 2 i 46 4 so 1 l 1 1 59 &-*-H- //u:

lag/MY W ATTORNEYS Filed Oct. 24, 1966 Sept. 24, 1968 H. w. WESTEREN ET AL 3,402,765

APPARATUS FOR USE IN CONSERVING WATER IN A FURNACE COOLING SYSTEM 3 $heet5$heet E- OOLING CHA FURNACE w TEMP. 68 REGULATOR l ov SUPPLY nn nnnn a HEAT EXCHANGER 34 54 56 FAN FIG. 4

INVENTORS HERBERT W WESTEREN WILLIAM H. KIMBALL y/J 7 7M ATTORNEYS United States Patent ABSTRACT OF THE DISCLQSURE Apparatus for conserving fluid in a cooling system wherein the heated fluid is removed from a cooling acket and recirculated in a closed system through a freestanding cabinet having a heat exchanger located therein, the fluid being directed through the heat exchanger for return to the cooling jacket.

The present invention relates to apparatus for use in conserving water in a furnace cooling system. More particularly, the present invention relates to apparatus that recirculates cooling fluid that is used in a furnace cooling system, thereby conserving the cooling fluid and eliminating the usual waste associated therewith.

It is the usual practice in the use of certain types of industrial furnaces to transfer articles that have been heat treated in the heat chamber therein to a cooling chamber, in which chamber the articles are cooled prior to removal from the furnace unit. Most of the prior known furnaces that employed a cooling chamber included a cooling jacket that surrounded the chamber and through which a cooling fluid was circulated. I-Ieretofore, after the cooling fluid, usually water, was circulated through the cooling jacket, it was then dlscharged to waste for disposal. However, in recent years water in certain areas has become less plentiful, and the use thereof has sometimes been restricted so as to conserve the water supplies. Since the problem of availability of water has become critical in certain areas, the present invention provides a system whereby the water used as a cooling fluid in furnaces is recirculated in a closed system and is thereby conserved.

In carrying out the concept of the invention, water which is used as the cooling fluid is circulated through a cooling jacket that is located around the cooling chamber of a furnace unit and is then directed to a dram tank. A pump transfers the water from the drain tank to a heat exchanger, the heat exchanger and drain tank being mounted in a free standing cabinet in which a fan is also disposed. The fan directs air from the floor on which the cabinet is located across finned tubes of the heat exchanger and, by so doing, removes the heat from the water that has been drained from the cooling chamber jacket to the extent that the water is discharged from the heat exchanger at a temperature that is sufficiently reduced for return to the cooling jacket. In order to precool the liquid as it is directed into the heat exchanger from the drain tank, the drain tank has a central duct formed therein through which a column of air is directed from the fan as it flows over the heat exchanger. The system may also be regulated so as to provide for introduction of additional water from an external source when the pressure in the system falls below a predetermined value.

Accordingly, it is an object of the invention to provide a closed system for use in the cooling system of a furnace, wherein a cooling fluid is continuously circulated in said closed system so as to avoid drainage of the fluid to waste.

Another object of the invention is to provide a sys- Ice tem for conserving furnace cooling water that includes a free standing cabinet having a drain tank located in an upper portion thereof and an air circulating fan located in the lower portion thereof, a heat exchanger unit being disposed between the drain tank and fan and receiving the warm water returns from the drain tank for removing the heat therefrom prior to recirculation to the furnace cooling jacket, the fan directing air through the heat exchanger unit and providing a means for precooling the warm water that is discharged from the furnace cooling system into the drain tank.

Still another object is to provide a system for conserving furnace cooling water wherein the pressure in the system is maintained at a sufficient value to supply the cooling requirements of the furnace cooling chamber, the system being arranged such that the pressures therein are sufliciently high to overcome the pressure of a fluid from an external source, thereby enabling the fluid from the external source to be supplied to the system when the pressure therein falls below the predetermined value. I

Other objects, features and advantages of the invention will become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.

In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:

FIG. 1 is a perspective view of the free standing cabinet in which the equipment that defines the system for conserving furnace cooling water embodied in the present invention is located;

FIG. 2 is a vertical sectional view of the free standing cabinet illustrated in FIG. 1;

FIG. 3 is a top plan view of the cabinet shown in FIGS. 1 and 2; and

FIG. 4 is a diagrammatic illustration of the system for conserving furnace cooling water as embodied in the present invention.

Referring now to the drawings and particularly to FIG. 4, a furnace is generally indicated at 10 and as shown is of that type that employs a conveyor unit on which metallic articles are placed for movement through a heat treatment chamber 12 during the heat treatment operation. Although the furnace as illustrated includes a moving conveyor on which the metallic articles are placed it is understood that the furnace 10 is merely representative of one type of a conventional heat treatment furnace with which the present invention may be utilized. Located rearwardly of the 'furnace heat treatment chamber 12 is a cooling chamber 14 into which the heat treated articles are moved after the heat treating cycle. During the cooling cycle, the articles are retained in the cooling chamber for a predetermined period of time, and a cooling fluid is circulated around the cooling chamber within a cooling jacket 16 that surrounds the cooling chamber 14.

Heretofore, it has been the common practice to discharge the cooling fluid circulated in the cooling jacket 16 to waste. However, the present invention provides a system for conserving the cooling fluid as used in a furnace cooling chamber, and in this connection reference is now made to FIGS. 1, 2 and 3 of the drawings. As illustrated in FIG. 1, the cooling system of the present invention includes a free standing cabinet generally indicated at 20 that is actually composed of three individual sections. As shown in FIG. 2, the free standing cabinet 20 includes a top section generally indicated at 22 in which a chamber 23 is located that defines a drain tank, a central section generally indicated at 24 in which a heat exchan er is located and a bottom section generally indicated at 26 in which a fan and pump unit are located.

3 Each of the sections 22, 24 and 26 is formed with appropriate side and end walls and are arranged so as to form the complete cabinet as illustrated in FIG. 1.

Referring again to FIG. 2, the top section in which the drain tank 23 is located includes a top cover 28 through which a drain pipe 30 extends, the drain pipe 30 communicating with a discharge port of the cooling jacket 16, as shown in FIG. 4. Located centrally of the drain tank 22 and projecting upwardly therethrough is a cylindrical duct 32 through which a column of air is passed for precooling the Warm water return that is discharged into the drain tank 22 from the cooling jacket 16. A water level 33 may be secured to a wall of the top section 22 and communicates with the drain tank 23 for indicating the level of the collected warm water therein.

Located in the bottom section 26 of the cabinet 20 and fixed to the bottom wall thereof is a pump 34 that is driven by a motor 36 through a chain drive 38. The pump 34, which is of any conventional construction, communicates with the drain tank 23 by way of a pipe 40, the pump 34 directing the warm water from the drain tank 22 through the pipe 40 and then upwardly through a pipe 42 for introduction into the heat exchanger 25 located within the central section 24. The heat exchanger 25 is defined by parallel pipes 44, 46 and 48 that are actually a continuous pipe communicating with the pipe 42 and on which a plurality of spaced fins indicated at 50 are fixed. The fins 50 thus serve to radiate heat outwardly therefrom for removing the heat of the warm cooling water as it is directed through the pipes 44, 46 and 48. As shown in FIG. 4, the pipe 44 communicates with an outlet pipe 52 that is adapted to direct the regenerated cooling water from the heat exchanger unit 25 back into the cooling jacket 16, as will hereinafter be described. A pressure gage 53 is also located in the line 52 and indicates the pressure of the water in the system as supplied to the cooling jacket, while a pressure switch 51 is also provided in the line 52 and acts to cut off the fan motor 56.

In order to sufliciently cool the water as circulated through the heat exchanger unit 25, a fan 54 driven by a motor 56 is provided and is conveniently mounted in the bottom section 26 just below the heat exchanger unit 25. The fan sucks air from the floor through a louvered opening and screens 57 and directs it over the heat exchanger pipes 44, 46 and 48 and fins 50 secured thereto to sufficiently reduce the temperature of the cooling water circulating through the pipes for use again in the' cooling system. As illustrated in FIG. 2, an opening indicated at 59 is formed in the bottom of the top section 22 and the top of the intermediate section 24, the opening 59 providing for communication of the duct 32 with the heat exchanger unit 25. It is seen that the column of air that is directed upwardly over the heat exchanger pipes is passed through the opening 59 and into the duct 32 for discharge at the top thereof. This arrangement provides for precooling the collected warm water that has been returned to the drain tank 23 and further forms a compact unit that avoids a separately located drainage tank and precooling unit.

It is contemplated in the operation of the system to maintain the temperature and pressure of the circulating water at predetermined values. For this purpose, a temperature regulator indicated at 58 in FIG. 4 is located in the drain pipe 30 and is interposed between the drain tank 23 and the cooling jacket 16. The temperature regulator 58 has communication with a thermostat or temperature responsive element 62 located in the cooling chamber 16 and thus provides for discharge of the cooling water through the pipe 30 when the temperature in the cooling jacket 16 exceeds a predetermined value. As further illustrated in FIG. 4, the water discharged from the heat exchanger 25 is directed back into the cooling 4 7 jacket by way of the pipe 52 and a line 60, a check valve 64 being located in the pipe 52 and preventing fluid from returning to the heat exchanger 25 if the pump 34 is shut down for any reason.

The pressure of the fluid discharging from the heat exchanger 25 is approximately 50 p.s.i.g. In order to supply additional water to the system if the pressure in the line 60 falls below the required value, a regulating valve 66 is provided and is located between a check valve 68 and a source of water supply, such as city water. The water is introduced from the source into the regulating valve 66 at approximately 70 p.s.i.g. and is regulated to approximately 45 p.s.i.g., which is somewhat below the operating pressure of the system. Since the check valve 68 is located between the regulating valve 66 and the normal flow path of the water, the liquid discharging from the heat exchanger 25 cannot flow toward the regulating valve. However, if the pressure in the system falls below 45 p.s.i.g., then additional water will be supplied to the system from the source of supply.

In operation of the system, it is seen that the water from the cooling jacket 16 is discharged through the pipe 30 and into the drain tank 23 where it is precooled by the air that is directed upwardly through the duct 32 by the fan 54. The precooled warm water located in the tank 24 is then pumped by way of the pipe 40 to the heat exchanger 25. After circulating through the heat exchanger 25 for removal of heat therefrom, the cooling water is then pumped upwardly through the pipe 52, check valve 64, line 60 for return into cooling jacket 16. If at any time the pressure in the cooling water passing through the line 60 falls below a predetermined value, additional water from the source is directed into the line 60 by way of the regulating valve 66 and check valve 68.

It is seen that the system that includes the free standing cabinet 20* is simple in operation, yet effective in providing for continuous circulation of the cooling fluid and without the discharge of the fluid to waste. The cabinet which includes the drain tank 23, heat exchanger 25 and bottom section 26 in which the fan and pump are located is both compact and effective in operation and may be employed in a variety of situations wherein a fluid is required to be continuously circulated through a cooling system.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept, and that the same is not limited to the particular forms herein shown and described, except, insofar as indicated by the scope of the appended claims.

What is claimed is:

1. In a furnace assembly, a heat treating chamber for heat treating metal aricles therein, a cooling chamber located adjacent to said heat treating chamber and receiving the heat treated articles after the heat treating operation for the cooling thereof, a cooling jacket located around said cooling chamber through which a cooling fluid circulates, and means for continuously circulating the cooling fluid through said cooling jacket without appreciably adding additional cooling fluid to the circulating cooling fluid, said circulating means comprising a closed system that includes a drain tank, said drain tank communicating with the discharge end of said cooling jacket for receiving cooling fluid, the temperature of which has been increased during the cooling operation, a heat exchanger communicating with said drain tank and receiving the heated cooling fluid therefrom and further communicating with the inlet end of said cooling jacket for directing the cooling fluid thereto after reducing the temperature of said cooling fluid, pump means located in said system for circulating the cooling fluid therethrough, means for precooling the heated cooling fluid prior to introduction into said heat exchanger and means for maintaining the cooling fluid at a predetermined pressure prior to introduction into said cooling jacket, a free standing cabinet located in close proximity to said heat treating chamber and cooling chamber and containing said drain tank, heat exchanger and pump means therein, said drain tank being located at the uppermost end of said cabinet and having a duct extending centrally therethrough, said precooling means including a fan that directs cooling air over said heat exchanger and through said duct, said cooling air being adapted to precool the heated cooling fluid discharged into said drain tank that surrounds said duct.

2. In a furnace assembly as set forth in claim 1, said heat exchanger being disposed between said fan and duct and receiving the heated cooling fluid from said pump that is interposed in circuit therebetween and said drain tank.

3. In a furnace assembly as set forth in claim 2, means responsive to the pressure of the fluid being discharged from said heat exchanger for supplying fluid from an external source if the pressure of the fluid is not suflicient to supply cooling requirements for said cooling jacket.

4. In a furnace assembly as set forth in claim 3, said fluid supplying means including a regulating valve that is operative to reduce the pressure of the fluid from said source to a pressure just below that of said system, wherein when the pressure in said system falls below the pressure of the regulated fluid from said source, suflicient fluid from said source will be added to the system to supply the cooling requirements for said cooling jacket.

5. In a furnace assembly, a heat treating chamber for heat treating metal articles therein, a cooling chamber located adjacent to said heat treating chamber and receiving the heat treated articles after the heat treating operation for the cooling thereof, a cooling jacket located around said cooling chamber through which a cooling fluid circulates, and means for continuously circulating the cooling fluid through said cooling jacket without appreciably adding additional cooling fluid to the circulating cooling fluid, said circulating means comprising a closed system that includes a drain tank, said drain tank communicating with the discharge end of said cooling jacket for receiving cooling fluid, the temperature of which has been increased during the cooling operation, a heat exchanger communicating with said drain tank and receiving the heated cooling fluid therefrom and further communicating with the inlet end of said cooling jacket for directing the cooling fluid thereto after reducing the temperature of said cooling fluid, pump means located in said system for circulating the cooling fluid therethrough, means for precooling the heated cooling fluid prior to introduction into said heat exchanger and means for maintaining the cooling fluid at a predetermined pressure prior to introduction into said cooling jacket, a free standing cabinet containing said drain tank, heat exchanger and pump means therein, said drain tank being located at the uppermost end of said cabinet and having a duct extending centrally therethrough, said precooling means including a fan located in the lower section of said cabinet, and said heat exchanger being located between said fan and duct, wherein said fan directs cooling air over said heat exchanger and upwardly through said duct, the cooling air from said fan precooling the heated cooling fluid that is discharged into said drain tank from said cooling jacket.

6. In a furnace assembly as set forth in claim 5, said cabinet including openings formed in the walls in the lower section thereof, said fan sucking air externally of said cabinet into the cabinet openings for directing it upwardly in a well defined column in said cabinet through said heat exchanger and outwardly through said duct.

7. In a system for recirculating a cooling fluid through a cooling jacket that is located in heat exchange relation with a chamber, a free standing cabinet located in relatively close proximity to said chamber and having a drain tank located at the uppermost end thereof, said drain tank communicating with the discharge end of said cooling jacket for receiving cooling fluid therefrom, the temperature of which has been increased while circulating in said cooling jacket, a heat exchanger located in said cabinet and communicating with said drain tank for receiving cooling fluid therefrom and further communicating with the innlet end of said cooling jacket for directing the cooling fluid thereto after the temperature of the cooling fluid has been reduced, pump means located in said cabinet and communicating with said drain tank and heat exchanger for circulating the cooling fluid therethrough, said drain tank having a duct extending centrally therethrough, and a fan located in said cabinet 'below said heat exchanger for directing cooling air over said heat exchanger and upwardly through said duct, said cooling air precooling the heated cooling fluid that is discharged into said drain tank that surrounds said duct.

References Cited UNITED STATES PATENTS 1,722,079 7/1929 Elmen 2663 X 2,057,518 10/1936 Fraser et al. 2663 2,633,108 3/1953 Sterick 145 X 2,967,694 1/1961 Cunningham 165107 X 2,995,647 8/1961 Bernard 165-107 X 3,196,939 7/1965 Erbe et a1. 165-107 ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner. 

